Can the sequence of objects created by the Array modifier be scaled down linearly?
The solution for this is the "Object Offset" of the Array Modifier.


Select the object with the Array Modifier and press Shift+S selecting to place the "Cursor to Selected"
Add an "Empty", which should result it being placed at the cursor aka same location as the object.
Go in the Array Modifier options and activate "Object Offset", followed by picking/selecting the "Empty" as target right below.

Now you can select the "Empty" and by scaling it each clone will recieve the scaling like this:

Be aware though that everything you do to the "Empty" now affects all the clones, moving, rotating, scaling as well as the combination of those can fast result in sometimes wanted, other times unexpected results.


Happy Blending